EAGER: Are the Dry Valleys Getting Wetter? A Preliminary Assessment of Wetness Across the McMurdo Dry Valleys Landscape

知识价值：直到最近，干谷的湿润土壤通常只在溪流和湖泊附近发现。自2002年温暖的南方夏季以来，无数？潮湿的地方吗?在远离海岸线的相对平坦的山谷底位置和山谷壁上的下坡流动手指处观察到。湿润这些土壤的水的来源尚不清楚，年复一年发生的时空格局也不清楚。它们的潜在意义是巨大的，因为土壤水分的增加可能会改变表层土壤的热力学、水文和侵蚀速率，并促进以前稳定的物质的运输。这些对土壤活性层的变化可以显著地改变干谷内的永久冻土和地面冰的稳定性。pi试图调查这些变化，以解决两个相互矛盾的假设：这些水的来源是什么？潮湿的地方吗?地面的冰融化了，这些水的来源是融雪。pi将使用Quickbird和Wordview卫星的高频遥感数据记录这些潮湿地区的时空动态，以记录2010- 2011年和2011- 2012年南方夏季湿点的发生、大小和增长情况。他们将通过确定每个季节是否在同一地点重复出现湿点来验证他们的假设，他们将使用存档图像比较现在和过去的分布。他们还将确定空间积雪模式和时间消融模式是否与湿点形成相一致。更广泛的影响：本项目将培训一名研究生。研究结果将在科学会议上报告，并发表在同行评议的期刊上。他们还将为“水文学发展模块课程”开发遥感应用于水文学的教学模块，并开发一个创新的原型项目，旨在利用公众参与，通过使用社交媒体和移动计算应用程序绘制干谷的湿点和积雪。

Intellectual Merit: Until recently, wetted soils in the Dry Valleys were generally only found adjacent to streams and lakes. Since the warm austral summer of 2002, numerous ?wet spots? have been observed far from shorelines on relatively flat valley floor locations and as downslope fingers of flow on valley walls. The source of the water to wet these soils is unclear, as is the spatial and temporal pattern of occurrence from year to year. Their significance is potentially great as enhanced soil moisture may change the thermodynamics, hydrology, and erosion rate of surface soils, and facilitate transport of materials that had previously been stable. These changes to the soil active layer could significantly modify permafrost and ground ice stability within the Dry Valleys. The PIs seek to investigate these changes to address two competing hypotheses: that the source of water to these ?wet spots? is ground ice melt and that the source of this water is snowmelt. The PIs will document the spatiotemporal dynamics of these wet areas using high frequency remote sensing data from Quickbird and Wordview satellites to document the occurrence, dimensions, and growth of wet spots during the 2010-­11 and 2011-­12 austral summers. They will test their hypotheses by determining whether wet spots recur in the same locations in each season, and they will compare present to past distribution using archived imagery. They will also determine whether spatial snow accumulation patterns and temporal ablation patterns are coincident with wet spot formation. Broader impacts: One graduate student will be trained on this project. Findings will be reported at scientific meetings and published in peer reviewed journals. They will also develop a teaching module on remote sensing applications to hydrology for the Modular Curriculum for Hydrologic Advancement and an innovative prototype project designed to leverage public participation in mapping wet spots and snow patches across the Dry Valleys through the use of social media and mobile computing applications.